kmandla@6m47421: ~/downloads$ steghide extract -sf 2014-05-10-6m47421-steghide-tux-embedded.jpg
Enter passphrase:
wrote extracted data to "secret.txt".
kmandla@6m47421: ~/downloads$ cat secret.txt
Now is the time for all good men to come to the aid of their country.

Well that was anticlimactic.😐 You can try it for yourself if you like. The password is 12345.

steghide has a lot options, and what you see above was just blatantly stolen from the quickstart guide. I imagine just about any file could be embedded into any other; like I said though, I didn’t try every variation.